1. Field of the Invention
The present invention relates to an ophthalmologic apparatus configured to measure an aberration of a subject's eye, and a method for controlling the same.
2. Description of the Related Art
In recent years, an ophthalmologic apparatus has included a scanning laser ophthalmoscope (SLO) apparatus, which scans laser light two-dimensionally on a fundus of a subject's eye, receives light reflected from the fundus, and acquires a two-dimensional image of the fundus, and an optical coherence tomography (OCT) apparatus, which acquires a tomographic image of the fundus using interference of low coherent light. The type of the OCT mainly includes a time domain OCT (TD-OCT) and a fourier domain OCT (FD-OCT). The type of the FD-OCT includes a spectral domain OCT (SD-OCT) and a swept source OCT (SS-OCT).
In recent years, the resolution of such an ophthalmologic apparatus has been increased by increasing the numerical aperture (NA) of a laser irradiation optical system. At this time, if a fundus of a subject's eye is imaged, measurement light needs to pass through an optical structure, such as a cornea or a crystalline lens, of the subject's eye. Thus, the captured image quality of a fundus image may be deteriorated due to an influence exerted by an aberration of the cornea or the crystalline lens. Therefore, an AO-SLO and an AO-OCT, which incorporate adaptive optics (AO) for measuring the aberration of the subject's eye and correcting the aberration into an optical system, are discussed in Y. Zhang et al, Optics Express, Vol. 14, No. 10, 15 May 2006. If the aberration of the subject's eye is measured, a Shack-Hartmann wavefront sensor system is generally used. This system first condenses a laser on a retina of the subject's eye, irradiates the condensed laser, and then receives light, which has passed through a pupil of the subject's eye, in reflected and scattered light from the retina using a sensor such as a charge coupled device (CCD) camera via a microlens array so that a wavefront can be measured based on a light receiving result. A wavefront correction device such as a variable shape mirror or a spatial phase modulator is driven so that the measured wavefront is corrected. Thus, a fundus having a high resolution can be imaged.